Most existing staplers include a stapling head, an intermediate magazine for carrying staples, and a base part, which are pivotally connected and movable relative to one another. In most such conventional staplers, when in use, a staple carried by the magazine is driven, by a driver at or adjacent a free longitudinal end of the stapling head, such that two parallel and spaced apart legs of the staple are forced through pieces of sheet material (e.g. paper). During the stapling action, the two legs of the staple are bent by an anvil carried by the base part towards each other and towards a crown of the staple joining the two legs. As the legs of the staple are bent whilst they are being driven through the pieces of sheet material, they will be curved after bending, which is neither satisfactory nor safe.
Thus, staplers have been developed which drive staples through pieces of sheet materials and the legs of the staples are straight after bending. Such conventional staplers (also known as “clinch staplers”) usually employ a two-step process. In the first step of the stapling process, a staple is driven away from the magazine by a driver of a stapling head such that the legs of the staple are driven through the pieces of sheet material. In the second step of the stapling process, the stapling head actuates an actuator which causes a plate carried by the base part to be retracted to expose a space, thus allowing the driver of the stapling head to drive the staple further towards an anvil carried by the base part so as to bend the legs in a quick action, thus resulting in two straight bent legs which abut an undersurface of the pieces of sheet material. It is best to synchronize the actuating movement of the stapling head with the time when the legs of the staple are fully driven through the sheets of sheet material, so as to obtain a good straight-bending effect on the legs of the staple. Such of course requires precise machining of the various components of the staplers. In addition, it is also found in practice that it is very difficult to machine the plate carried by the base part to the appropriate dimensions to achieve the desired movement. In addition, the two steps of this stapling process are discontinuous and uncomfortable to a user.
It is thus an object of the present invention to provide a stapler in which the aforesaid shortcomings are mitigated, or at least to provide a useful alternative to the trade and public.